DE1498151A1 - Circuit arrangement for integrating unique, fast-running processes - Google Patents

Description

WPLrINO-RUDOLFBJBKACH U QÖTTINGEN-POTTERWEQ 6

! TaEFON 57323

Dipl.IngoDreBr.h.c Haas List, Graz (Austria)

Circuit arrangement for the integration of unique, rapid processes

In some areas of measurement technology there is a need to integrate the measured variables over certain areas, ZoB * time or distance segments, in order to obtain the measurement result sought Pressure according to the time _e In the same way, one obtains the work of deformation from force and path, the energy from power and time, the electrolytically converted amounts from current strength and time, the amount of converted radioactive substances, the blackening and much

BATH

909803/0784

similar measured values. such as the trichromatic values at the color measurement »

The integration by means of one of the well-known devices, e.g. a Miller integrator, returns for one-off and very fast processes only inadequate results, and additionally requires a subsequent evaluation or assessment of the integral curve obtained, so must in these appeal to the possibility of integrating by determining the area, (Counting, weighing, planimizing) or »a graphic integration, or a numerical method (Simpson's rule), which is based on a quadratic interpolation based, can be used. The records required for this (Oscillograms) of the function to be integrated and the subsequent integration process are with a high expenditure of time and, in many cases, considerable material costs related »There are also special difficulties with most of the known electrical integration methods, if should be integrated not according to time, but according to some variable dependent on time. An exception only a well-known integration system offers this, but it works with mechanical integration gears »

The invention eliminates the difficulties referred .by creating a circuit which he enables ■:. ■ '[light, the numerical integration methods to electronic, base or no maintenance quickly and accurately with minimal scarf - * apply "This circuit is characterized it - According to the invention in that a frequency-modulatable sawtooth

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generator is provided, which preferably. a known Yierschichtdiode-SG storage with a! transistor as Iiadewiderstand contains, nand that the sawtooth frequency by means of adjustable working resistance of the transistor - cash and through, one delivered to the entrance of the iransistor Time function can be influenced that the sawtooth generator sin Impedance converter and this a known voltage « -Comparator for comparing the periodic Sage tooth tension is connected downstream with the voltage to be integrated, and that the Spaimungskomparator is followed by a UND gate, on whose the second input is a frequency-constant voltage that by means of the frequency and width modulated pulse voltage of the voltage comparator in pulse columns via the TTND ^ Satter can be fed to a digital counter connected downstream, with integration limits in the form of a real-time pulse the gate of the digital counter or a third input of the ÜUE gate can be initiated. With this circuit arrangement appears in a similar way to the nw & erischen method electronically the Jläehe enclosed by the curve divided into equal strips of area «The intfgratioa takes place by determining the amplitudes of the surface strips and then Sum formation between the. specified orenZen. The decomposition of the yon of the curve to be integrated y = f (x) enclosed area in Fläoihenstoeifen ejpffollowed by the Sägezahngenfiratpr, whereby the through the subsequent frequency of the saw <tooth generator given free te of the surface strips in meadows » by changing the internal resistance of the 4th transistor

BATH ORIGINAL

and adjusted with its adjustable working resistance can be·

If the integration takes place according to any time function, so this can be given to the input of the transistor and thus the strip width in the corresponding dependency be brought by the time function »Since the sawtooth voltage in the circuit according to the invention over an impedance converter reaches the voltage comparator, any undesired frequency influencing is avoided as In the simplest case, the voltage comparator can be a Schmitt trigger Find use, whereby the provision by the ' sloping plank of the sawtooth took place Amplitude of the function to be integrated. The width of the However, pulses also corresponds to the number of frequency-constant numerical frequencies reaching the counter. The counter counts adding up the impulse columns and thus forms the integral of the function. The integration limits are determined by the Gate pulse introduced, which the counter during this time for the Enables counting process. For meters that do not have a gate control, the gate pulse can also be sent to the third input of the AND gate are given,

With a suitable choice of the sawtooth frequency and the counting frequency, a very high level of accuracy and high resolution can be achieved. Especially with slow processes the resolution is limited primarily by the '■ storage capacity of the digital counter * · used ·

Further details and advantages of the invention The circuit arrangement is based on the description below of exemplary embodiments on the basis of the drawing, It ' Fig. 1 shows the circuit diagram of a former embodiment of the invention with digital Meßwerterfassuhg, Fig «2 a Schematic representation of the Meßtrorganges in diagram form and FIG. 3 the circuit diagram of a second embodiment of the Circuit arrangement according to the invention for analog display, only that part of the circuit which differs from the embodiment in FIG. 1 is shown.

The circuit arrangement comprises a sawtooth generator 1, the one known per se Viersohiohtdiodensehaltung 2 with contains a transistor 3 as a charging resistor. The transistor 3 is assigned a controllable working resistor 4. With 5 the input of the sawtooth generator 1 is designated, Dem Sawtooth generator 1 is an impedance converter 6 and this one known voltage comparator 8 with an input for the voltage to be integrated 9 downstream »7 denotes the sawtooth voltage used for voltage comparison» The voltage comparator 8 is followed by an AND gate 12 and • this is followed by a digital counter 15. At the second input of the AND gate 12 is a constant frequency voltage 11. Integration limits in the form of a Lechteokimpulses 14 are either above a third input of the AND gate 12 or via the gate of the digital counter 15 can be initiated. With 10, the frequency and width modulated .Impuls-j emanating from the voltage comparator 8 voltage and with 13 one of the digital counters 15 Impulse columns denoted "

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Referring to Jig. 2 results in the following mode of operation of the circuit arrangement according to the invention. The breakdown of the area enclosed by the curve y = f (x) (9 in Pig · 1 and 2) to be integrated into strips of width X ₁ (7) is carried out by the sawtooth generator 1. The The surface width x of the strip is given by the repetition frequency of the sawtooth generator 1, which can be set within certain limits by changing the internal resistance of the transistor 3 and by means of its adjustable working resistance 4 '.

As long as the integration is not based on time but according to another variable, for example a time function χ a f (t) takes place, this function is applied to d * n input 5 of the transistor 3 and thus the strip width x ^ brought into the corresponding dependence on the function χ = f (t). The output from the sawtooth generator 1 and through The sawtooth voltage 7, which is kept free of undesired frequency influences on the impedance converter 6, is used in the voltage comparator 8 is compared with the function y = f (x) (9) to be integrated. As a voltage comparator, in the simplest case a Schmitt carrier can be used, the reset being effected by the falling flank of the saw tooth. The voltage comparator 8 thus provides a frequency and width modulated pulse voltage 10 in the form of square pulses »these correspond in their width B to the amplitude y "der Function y »f (x) at a distance χ · During the duration B of / leohteokimpulses 10 becomes the frequency constant voltage 11

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passed as a counting frequency via the AND gate 12 to the digital counter 15. The width B _{n of} the right pulses 10 corresponds to the number N of the counting frequency 1.1 'and H _n «y_. And ιέ =% _n .

The counter 15 counts the pulse columns 13 and 13 by adding up

forms the integral of the function y = f (x) · the gate pulse 14 with the duration χ = n- to χ = η provides the integration limits, by releasing the counter 15 for the counting process during this time. For meters without gate control, the Gate impulse 1 £ given to the third input 16 of the AND gate 12

For the analog representation of the process to be integrated, the digital counter 15 is represented by the one shown in FIG Circuit part replaced. The input of this circuit part form a diode 17 followed by a resistor 18 which is connected to the input of a field effect transistor 20. With the resistor 18 is a via a button 24 discharged Capacitor 19 in series. The field effect transistor 20 is a Measuring bridge with moving coil measuring mechanism 21 and potentiometer 23 for Zero point adjustment. Downstream. The integration tension for oscillographic recordings is at the working resistance 22 of the field effect transistor 20 can be removed. -

The function of the so-holding part described is the following: The pulse columns 13 coming from the AND gate 12 charge the capacitor 19 via the diode 1.7 and the resistor 18. The charge of the capacitor 19, that of the number of pulses is proportional, is via the field effect transistor 20 with

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the moving coil measuring mechanism 21 measured in bridge position »The. at the Work resistance. 22 removable charging voltage can be used for illustration of the integration process are fed to an oscilloscope. The charge on the capacitor 19 will soon take place Measurement carried out by button 24 »

In many applications it is necessary that a fluctuating zero line be taken into account in the integration In the above-described postural arrangements this can be done by connecting a differential amplifier in front of the input 9, the to be integrated Voltage connected to the two inputs of the differential amplifier will"

Claims;

λ η ο ηο / η -π ο ι

Claims (1)

Claimsϊ S ohaltungaanor dnung for the integration of one-time, fast · moving gate corridors according to the time or any puncture depending on the time, characterized in that a frequency-modulatable sawtooth generator (1) is provided, which is preferably a four-layer diode circuit (2) known per se with a! Contains transistor (J) as a charging resistor, and that the sawtooth frequency is adjustable by means of the controllable working resistor (4) of the transistor (3) and can be influenced by a time function delivered to the input (5) of the translator (3), so that the sawtooth generator ( 2) an impedance converter (6) and this, a known voltage comparator (8) for comparing the periodic sawtooth voltage (7) with the voltage to be integrated, (9) is connected downstream, and that the voltage comparator (8) is a UHD gate ( 12) follows, at the second input of which there is a frequency constant voltage (11), which is generated by means of the frequency- »and width-modulated pulse voltage (1 0) of the voltage comparator (8) can be fed in pulse columns (13) via the TJBB gate (12) to a digital counter (15) connected downstream of this, with integration limits in the form of a square pulse (H) via the gate of the digital counter (15) or a third Input of the AND gate (12) can be introduced · '...'. 909803/07 84 - ίο - 2. Circuit arrangement according to claim. 1, for analog display of the process to be integrated, 'characterized in that the square pulse (14) at the third input of the MD gate (12) is initiated that the AND gate (12) a diode (17) and this a resistor (18) for charging a capacitor (19) connected in series with it and discharged via a button (24) is connected downstream, and that the capacitor (19) is connected to the input of a subsequent one Field effect transistor (20) is connected to which a measuring bridge with moving coil measuring mechanism (21) and potentiometer (23) for zero point adjustment follows, with the work resistance (22) of the field effect transistor (20) the integration voltage for oscillographic * recordings is removable » 3. Circuit arrangement according to claim 1 or 2, characterized in that that the voltage comparator (8) has a differential amplifier at its input for the voltage to be integrated (9) is connected upstream, at the two inputs of which the voltage to be integrated (9) is given o 22.6.65 3 / 0-784